Electric switch



c. P. RANDOLPH ET AL ,236

June 4, 1940.

ELECTRIC SWITCH Filed April 26, 1938 4 Sheets-Sheet 2 im h r 30 UH s at e m m h ,AUJA m we @n .m P3 .n 8% T Wm. H rD 53 E. C. Randolph June 1940' c. P. RANDOLPH El AL 2203236 ELECTRIC SWITCH Filed April 26, 1938 4 Sheets-Sheet 4 Fig.2].

90b Inventors: Charles P. Randolph,Deceased, .B g E-ORanciolph and. Do

rothy Sane Executor-s,

AWa Leslie A.Kempt.on,

Them Attorneg Patented June 4, 1940 PATENT OFFICE;

2,203,236 i nmc'rmc swrrcn ewe r. Randolph, deceased, late of Oak Park, Ill., by E. C. Randolph and Dorothy Saner,

executors,

Oak Park, 111.,

and Leslie A.

Kempton, Chicago, IlL, assignom to Edison General Electric App a ce Company, Inc., a corporation of New York Application April 26, 1938, Serial No. 204,334

9Claims.

This invention relates to electric switches, more particularly to multiple-position electric switches, and it has for its object the provision of an improved device of this character.

While not limited thereto, this invention is especially applicable to multiple-position electric switches for controlling electric range heating elements to provide a plurality of heating effects; and it contemplates an improved multiple-position switch which in its basic principles of construction and operation is adapted to a wide variety of uses and applications. For example, it can be used to control the surface but plates to provide various degrees of heat, ranging from comparatively high to relatively low heat intensities; and also to control the heating means of an oven to provide preheat, bake and broiling heats.

For a more complete understanding of this invention, reference should be had to the accom panying drawings in which Fig. 1 is a front elevation of an electric switch embodying this invention; Fig. 2 is a rear elevation of the switch shown in Fig. 1 with a part removed so as to illustrate certain details of construction; Fig. 3 is a sectional view taken through the line 3-3 of Fig. 2 and looking in the direction of the arrows, the switch of Fig. 3 being shown mounted on a supporting panel; Fig. 4 is a sectional view taken through the line 44 of Fig. 3 and looking in the direction of the arrows; Fig. 5 is a fragmentary sectional view taken through the line 5-5 of Fig. 4 and looking in the direction of the arrows; Figs. 6-11 inclusive are diagrammatic representations of the switch of Figs. 1-5 showing the switch controlling a heating element having two resistances to provide various degrees of heat; Fig. 12 is a front elevation of a switch of modified form arranged in accordance with this invention; Fig. 13 is a rear elevation of the switch of Fig. 12 having a part removed so as to illustrate certain details of construction; Fig. 14 is a sectional view taken through the line i l-l4 of Fig. 13 and looking in the direction of the arrows, the switch being shown mounted upon a supporting panel; Figs. 15-18 inclusive are diagrammatic representations of the switch of Figs. 12, 13 and 14 and showing the switch controlling a two resistance heating element to provide a number of degrees of heat loss than the number efiected by the switch of the first form shown in Figs. 1-11; and Figs. 19-23 inclusive are diagrammatic representations of another form of switch arranged in accordance with this invention, this switch being particularly intended to control the heating elements of an elecheats.

tric oven to provide preheat, bake and broiling Referring more particularly to Figs. 1-5, this invention has been here shown in one form as applied to a switch intended to control the hot plate of an electric range. This switch comprises a supporting panel Ill formed of a suitable electrically insulating material, such as a phenol condensation product. Preferably, the panel l0 will be molded of the insulating material. The panel is provided with an upright peripheral flange l I which defines a rectangular-shaped chamber [2. Mounted within the chamber l2 at one end thereof, the lower end as viewed in Fig. 2, and secured to the panel are a series of line terminals I3, l3a, and 13b. Preferably, the line terminals will be secured to the panel by molding sections of the terminals into the body of the panel, as shown more clearly in Fig. 3. The terminals, as shown, projectthrough the lower end wall of the chamber l2 so that line connections can be made exteriorly of the chamber.

Mounted within the upper end of the chamber 12 and molded in the panel I 0 are a series of terminals I 4, I la and b which are intended to be connected with the heating element or load being controlled. These terminals "have portions exposed at the upper end of the front wall surface of the panel III, as shown in Figs. 1 and 2, and threaded into these exposed portions are binding screws l5.

Mounted within the chamber l2, and interposed between the line terminals l3, Ba and 13b and the load terminals [4, Ma. and llb are a series of contact fingers IS, IT, l8, i9, 20 and 2|. The contact fingers l8 and I1 are rigidly secured at their lower ends, as viewed in Figs. 2 and 3, to the line terminal I 3. At their opposite ends they carry contacts 22 and 23 that cooperate with fixed contacts 24 and 25. Contact 24 is mounted on the load terminal l4; contact 25 is mounted on a conducting bracket 25 which is rigidly secured to the panel l0 within the chamber l2 in any suitable manner, as by means of rivets 21. The bracket 26, as shown, extends transversely. of the chamber from the contact 25 over to the opposite side of the chamber where it is mechanically and electrically connected with the load terminal Mb through the medium of the rivet 21.

The contact finger I8 is rigidly secured at its upper end to the central load terminal Ma and at its opposite end carries a contact 28 that cooperates with a fixed contact 29 mounted on the center line terminal I311.

The next contact finger l9 to the right is rigtherefore, connects the two heating resistances 51a and III) in parallel to the high voltage across the outside line wires "a and 58b. This provides the highest heat generation in the system shown in Figs. 6-11, and will be designated the "Speed" heat.

Now if the knob 56a be turned another 60 in the clockwise direction to position of Fig. 8, the switch finger ii is opened, while the switch fingers It and it are closed. This operation disconnects the resistance 51a from the supply source, but leaves the resistance Slb connected across the high voltage lines 58a and 5812. This will establish a lower heating rate which will be designated Half heat.

Alower heat generating rate, designated Quarter heat, is established by turning the knob 56a 60 farther in the clockwise direction to the position of Fig. 9. In this position of the switch, the fingers I6 and I9 only are closed, and therefore, the two resistances 51a and 51?) are connected in series across the high voltage source 5801 and 5817.

A still lower heat generation, which we will call Thrift heat, is obtained by advancing the knob 55 a 60 farther in the clockwise direction to the position of Fig. 10 wherein the contact fingers IE and 29 only are closed. In this position of the switch, the resistance 51?) only is connected to the low voltage across one outside wire 58b and the neutral wire 58c.

The lowest heat obtainable in the system of i Figs. 6-11, designated Warm heat, is effected when the switch is moved to its position of Fig. 11 wherein the two fingers l6 and 2! only are closed. In this position, the two resistances 57a and Eli) are connected in series tothe low voltage across the outside wire 58b and the neutral wire 58c.

It will be understood that when the switch is used to control the hot plate of an electric range, the switch will normally be mounted in a panel Bil positioned vertically at the front of the range and that the shaft 44 will protrude through this panel, and the knob 560 so mounted as to be accessible at the front of the panel. is used to mount the switch on the panel, and for this purpose it is provided with a pair of threaded apertures 6! into which screws 62 in the panel are threaded, as clearly shown in Fig. 8.

In Figs. 12-18 there is shown a switch of modified form arranged in accordance with this in vention and adapted to control a two resistance heating element to provide but three heats instead of five heats as in the first form. This switch comprises an insulating panel and housing 64 arranged in substantially the same fashion as is the panel and housing of the first form. Mounted within one end of the chamber 65 of the housing are three line terminals 66, 66a and 86b. Mounted in the opposite end are three load terminals 61, 61a and 61b. Attached to these three load terminals are binding screws 68. Mounted within the chamber 55 are four resilient switch fingers 69, 10. H, and 12. The finger 69 is rigidly secured at its lower end to the line terminal 66, the finger 10 to the line terminal 66a, and the two fingers H and 12 to the line terminal 66b. At their upper ends, the contact fingers carry contacts 13 that cooperate with a series of fixed contacts 14. The contact on finger 69 is associated with a fixed contact mounted on the load terminal 81, those on fingers l0 and H with fixed contacts secured to the load terminal 810,

The casing 41 and the contact on finger 12 with a fixed contact on load terminal 61b.

As before, the four contact fingers are biased to close the associated contacts by the inherent resiliency of the fingers. They are operated to open the contacts by a series of pins 15 mounted in a series of apertures provided for them in the switch panel and projecting through to the opposite side where they are operated by a cam 16. The cam 76 is provided with an operating shaft 11, with a positioning cam 18 on the shaft and with which resilient springs 19 are associated to position the shaft. The cam 16, positioning cam 18 and springs H! are all housed in a casing 80 which supports springs 79, and also holds the positioning cam 18, shaft ill and cam 16 in their proper assembled relation. The housing is attached to its supporting panel M by means of screws 82. In this case, the switch has four positions, and the positioning cam. is formed with four equal sides.

In Figs. 15-18, this switch mechanism is shown diagrammatically as controlling the resistances 82 and 83 of a heating element 86, selectively connecting them to a three-wire supply source having two line wires 85 and 85a and a neutral wire 851), these wires being connected respectively to the line terminals 66a, 66 and 66b. The load terminal 81a is connected to the left-hand end of the resistance 82, while the right-hand end of resistance 83 is connected to load terminal El. The other ends of these resistances are connected together and to the load terminal 67b. Here also, the voltage between the outside wires 85 and 85a is substantially double that between each outside wire and the neutral 8%.

In Fig. 15, the switch is shown in its Off position. In this position only the finger 72 is closed, thereby connecting the connected ends of the resistances to the neutral wire 8%.

The switch is advanced 90 in a clockwise direction from the position of Fig. 15 to-the position of Fig. 16 to effect the High heat condition in the heating element 83. When the switch is advanced to this position, the fingers 69, 10;

and 12 are closed. This connects the outside ends of the two resistances 82 and 83 in parallel to the high voltage across the line wires 85 and 85a, while their common connection is connected to the neutral 8512.

Medium heat is effected by advancing the switch 90 farther in the clockwise direction, which operation establishes the connections shown in Fig. 17. Here the contact fingers 69 and 12 are closed to connect the resistance 83 only to the low voltage between the outside lino wire 85a and neutral wire 85b.

Low heat is effected by advancing the switch another 90 turn in the clockwise direction to establish the connections shown in Fig. 18. Here the fingers S9 and H are closed to connect the two resistances 82 and 83 in series to the low voltage across the outside lino wire 85a and the neutral 85b.

In Figs. 19-23 inclusive there is shown a fiveposition switch 86 of modified form arranged in accordance with this invention, and shown controlling the heating elements 81, 88 and 89 of an electric oven by selectively connecting them with a three-wire supply source having two outside wires 90 and 90a, and a neutral wire 901); the voltage between the outside wires is substantially double that between each outside wire-and the neutral. It is to be understood that the two heating elements 81 and 88 are positioned in the top of the oven, while the heating element 89 is'positioned in the bottom of the oven.

It is contemplated that the switch 86 will'control the heating elements 81, 88 and 89 to provide a preheat, two baking heats, and a broiling heat. This switch has three terminals adapted to be connected with the line wires 90, 99a and 90b and with five load terminals adapted to be connected with the conductors 9|, Ma, 9"), Me and 9| d which are connected with the terminals of the resistances 81, 88 and 89, as shown diagrammatically in Figs. 19-23. These line and load terminals are of the same form as the line and load terminals of the first two forms of this invention. There are six switch fingers 92-92e, the finger 92 is electrically connected to the load terminal of wire 98, finger 92a to load terminal of wire 9la, finger 92b to line terminal of wire 90a, finger 920 to load terminal of wire Sic, finger 92d to the line terminal of wire 98b and finger 926 to line terminal of wire 90. These fingers cooperate with fixed contacts 93-93e respectively; fixed contact 93 is connected to the load wire 9|, contact 93a to line wire 90, contact 9322 to load wire 9"), contact 930 to the line terminal of wire 90a, contact 93d to the terminal of load wire Me, and contact 936 to the load terminal of wire Sid.

The switch is shown in its Ofi position in Fig. 19 in which all of the fingers are in their open switch positions. When the switch is advanced 72 in a clockwise direction from Fig. 19 to the position of Fig. 20, the fingers 92, 92a, and 92b are closed, while the remaining fingers are in their open positions. This effects Preheat of the oven by connecting the upper heating element 88 and the lower heating element 89 in parallel acrossthe high voltage between the outside wires 90 and 90a.

Preheat may be used not only to preheat the oven, but may also be used for certain baldng operations, such as baking biscuits, where it is desired promptly to obtain a fairly large radiant heat input at the top of the oven, without waiting for the oven lining to preheat by convection from the bottom heating element. This heat may also be used in meat roasting when it is desired to have the outside of the meat wellbrowned and the inside rare.

When the switch is advanced from the position of Fig. 20 to the position of Fig. 21 through an angle of 72 in the clockwise direction it establishes an oven heat which will be called Bake 1. In Bake 1 heat, there is provided a mild radiant heat in the top of the oven which is desirable in baking cakes and pies starting with a cold oven. This also provides a more even heat distribution throughout the oven. It will be observed that when the switch is in its position of Fig. 21, the fingers 92a, 9%, 92d and 92e are closed, while the fingers 92 and 920 are open. In this position of the switch, the'lower heating element 89 is connected to the high voltage source across the line wires 90 and 9011, while the upper heating element 8'I'is connected to the low voltage source across the outside wire 90 and the neutral wire 9012. This provides heat in the lower part of theoven and the mild radiant heat at the top.

A second baking heat, which will be called Bake 11, provides heat only at the bottom. This is desirable at times, particularly when the oven is loaded to capacity, and where .it is not desirable to brown the food too much. This heat is established by moving the switch to its position of Fig. 22, which is 72 in advance of the position of Fig. 21. Here the fingers 92a and 9211 are closed while the remaining fingers are open. This connects the lower heating element 89 to the high voltage source across the line wires 99 and 90a, while the remaining elements 81 and 88 are deenergized. This supplies heat to the lower part of the oven only.

A Broiling heat is established in the upper part of the oven only by moving the switch to its position of Fig. 23, which is 72 in advance of its position shown in Fig. 22. Here the fingers 92, 92b, 92c and 92s are closed, while fingers 92a and 92d are open. This connects the two upper heating elements 81 and 88 in parallel to the high voltage source between the outside line wires 99 and 99a.

Itis to be understood that the arrangement of the line and load terminals and the contact finge'rs will be substantiallythe same as in the first forms of the invention described, except as to number, and that they will be mounted in a similarly arranged housing. They are operated by a cam plate 94 which actuates the fingers by means of pins 95 all arranged as are the corresponding elements of the first two forms, except of course that the cam plate will be provided v with the properly arranged depressions to effect the cycle of operation described in connection with Figs. 19 to 23. The cam plate will further be provided with a positioning cam (not shown) having five sides, and an operating knob all as arranged in the manner previously described in connection with the first forms shown.

While we have shown particular embodiments of our invention, it will be understood, of course, that we do not wish to be limited thereto since many modifications may be made, and we, therefore, contemplate by the appended claims to cover any such modifications as fall within the true spirit and scope of our invention.

What we claim as new and desire to secure by Letters Patent of the United States is:

1. A switch mechanism comprising an insulating supporting panel, contact fingers on one side of said panel biased to predetermined controlling positions, pins slidably mounted in said panel opposite said contact fingers adapted to engage them to operate them from said positions and extending through to the opposite side of said panel, a cam plate on said opposite side mounted to revolve to selected positions and to engage said pins to force them inwardly and thereby operate said fingers in a predetermined cycle of operations as the plate is revolved to said positions, said cam plate bearing against said side of said panel so that the panel functions as a bearing surface for said cam plate, and means for operating said cam plate to said positions.

2. A switch mechanism comprising an insulating supporting panel, cdntact fingers on one side of said panel resiliently biased to predetermined controlling positions, actuating members slidably mounted in said panel opposite said contact fingers adapted to engage them to operate them from said positions and extending through to the opposite side of said panel, a cam plate on said opposite side bearing on said side so that said side functions as a bearing surface for said cam, and said cam mounted to revolve to selected positions and to engage said actuating members to force them inwardly and thereby operate said fingers in a predetermined .cycle of operations as the plate is revolved to said positions, and a housing for saidcam plate mounted on said opposite side of said panel and cooperating with said plate to hold it against said side.

3. A multi-position switch mechanism comprising a supporting panel, contacts on one side of said panel biased to predetermined controlling positions, pins mounted in a series of apertures in said panel opposite said contacts arranged when depressed to operate them from said posi- 1 tions and projecting through to the opposite side -01 said panel, a cam plate on said opposite side having a series of cam surfaces arranged when the plate is rotated to depress said pins to operate said contacts in a predetermined cycle of operation, a cup-shaped member on said opposite side of said panel housing said cam plate, an operating shaft for said cam plate having an inner bearing in said panel and an outer hearing in said cup-shaped member, a positioning cam within said cup-shaped member on said shaft secured to said cam plate-and engaging said cup-shaped member so as to hold said cam plate in its operative position in said member, and springs in said cup-shaped member engaging 26, said positioning cam resiliently to locate said shaft and cam plate in the controlling positions of the cam plate.

4. A switch comprising an insulating panel, a plurality of contact fingers mounted on one side of said panel, a metallic operating cam on the opposite side of said panel, insulating pins in said panel extending through it for operation by said cam and to operate said contact fingers, a shaft for operating said cam plate, a'

metallic member housing said cam plate, an insulating positioning cam within said housing connected to said shaft and engaging said cupshaped member so as to hold said cam inits operative position in said member, fiat springs 40 in said housing extending from side to side having their mid-sections engaging said positioning cam to locate the cam and thereby the shaft and cam plate, and the springs having projections on their ends received in apertures in said casing to secure the springs within said housing.

5. A switch mechanism comprising an insulating housing member formed by bottom and side walls molded of an electrically insulating material, a first series of terminals molded in one end of said housing, a second series of terminals molded in the opposite end of said housing, resilient contact fingers within said housing connected with said first series of terminals extending across -said housing for cooperation with said second ,series of terminals and biased into predetermined positions with relation to them, a series of actuating members mounted in a series of apertures provided for them in said bottom wall under said contact fingers arranged when moved in- GCfi-wardly to engage said fingers to move them into "other predetermined positions with relation to said second series of terminals, a cam plate outside of said bottom wall arranged when rotated to move said actuating members inwardly in a predetermined order, a housing encasing said cam plate attached to said bottom wall, and an operating shaft for said cam plate protruding from said housing. 6. A switch mechanism comprising an insulating housing molded of an electrically insulating material having bottom and side walls defining a chamber, a first series of terminals molded in one end of said chamber, a second series of terminals molded in the opposite end, resilient con- 75 tact fingers within said housing connec ed with said first series of terminals extending across said chamber and biased into engagement with contacts on said second series of terminals, a series of insulating pins mounted in a series of aper= tures provided in said bottom wall of said housing under said fingers arranged when moved inwardly to engage said fingers to open said contacts, a cam plate outside of said bottom wall bearing on the outer surface of said wall and arranged when rotated to move said pins mwardly in a predetermined order, a metallic housing attached to said bottom wall encasing said cam plate, an operating shaft for said cam plate protruding from said metallic housing, a positioning cam in said housing attached to said shaft, re silient means in said housing engaging said positioning cam to position the shaft and cam plate, saidpositioning cam also bearing, against said housing to hold said cam plate against said bottom wall, and an insulati g cover enclosing the opposite side of said insulating housing.

7. A multi-position switch mechanism comprising a supporting panel, contacts supported by said panel on one side thereof biased to predetermined controlling positions, pins mounted in a series of apertures through said panel opposite said contacts arranged when depressed to operate them from said positions and projecting through to the opposite side of said panel, a cam plate on said opposite side having-a series of cam surfaces arranged when the plate is rotated to depress said pins to operate said contacts in a predetermined cycle of operation, a cup-shaped member housing said cam plate and having a series of fingers projecting inwardly and received in apertures provided for them in said panel so that said panel is supported directly by said casing, and means mounted in said cup-shaped member for operating said cam plate.

8. A switch comprising a panel, switch fingers on one side of said panel, a cam on the opposite side provided with a cam surface that has a running clearance with said side, means operated by said cam controlling the operation of said switch fingers, an operating shaft, means securing said cam to said shaft, a casing secured to said opposite side housing said cam, the shaft protruding from the casing, operating means on the outside of the casing secured to said shaft, a collar within said casing secured to said shaft, and a spacer within said casing secured to said shaft and bearing both on said casing and col-= lar so as to hold said shaft and cam'in their operative positions.

9.-A switch mechanism comprising an insulating housing molded of an electrically in'sulating material having bottom and side walls defining a chamber, a first series of terminals molded in one end of said chamber, a second series of terminals molded in the opposite end of said chamber, resilient contact fingers within said housing connected with said first series of terminals extending across said chamber and biased into predetermined positions with relation to contacts on said second series of terminals, a series of insulating members mounted in a series of apertures provided in said bottom wall of said housing under said fingers arranged when moved inwardly to engage said fingers to move them to other predetermined positions with relation to said contacts, a cam plate outside of said bottom wall bearing on the outer surface of said wall and arranged when rotated to move said insulating members inwardly in a predegaging said positioning cam to position said shaft and cam plate.

Emecutors of the Esta Deceased.

E. C. RANDOLPH, DOROTHY SANER, te of Charles P- Randolph, 5

LESLIE A., KEZMPTON.

Julie 4, 1946. D. E. BONNER MACHINE FOR CLEANSING AND TREATING Filed May 5, 1939' 4 Sheets-Sheet 1 M w M M INVENTOR. ,ZDoua; as ,.Ba/v/v/g ATTORNEY 

